Fuel System Flashcards
Where pylons can be installed?
2, 5
The booster pump is housed in
The flight sump
The flight sump contains fuel for
20 to 23 sec neg g at max throttle
FUEL SHUT-OFF VALVE is powered by
Essential bus
How long does it take to dump fuel?
2 min for 3/4
6 min for 1/4
Fuel dump allows to dump fuel contained in
Tip tanks
FUEL DUMP system is alimented by
Essential bus
Fuel qty is collected by sensors in the tanks and is sent to
EDAB for showing on MFDs
When fuel qty goes below the selected bingo, what happens in the cockpit?
Fuel warning audio message
MASTER CAUTION light
In SYS format, the fuel is displayed in amber background
F. TRANS turns on when
When fuel transfer rate is below normal values
Fuel qty in fuselage tank is 500 +30/-20kg, w/ at least 45kg in tip tanks
F. LOW turns on when
Fuselage tank below 210+-20kg (F34)
Fuel used for 339CD is
NATO F-34 (JP-8)
F. UNBAL turns on when
60kg for 12 sec
The error in fuel measurement from sensors is
+-15kg and 2% of the indication
The unusable fuel in tip tanks is
10kg
Minimum fuel qty in each tip tank is
10kg (they are considered empty)
Nominal density F-34
0.803 kg/dm3
Name of the Air refueling nozzle
MA-2 standard
How many inlet valves are there in the fuel system?
3
How many vent/safety valves are there?
1
How valves are open/close during air to air refueling?
By pushing the AR/ON/FAIL push button they are open
They close automatically as the selected qty of fuel is reached or if the air refueling switch is put back to off
When does the probe nozzle valve open?
At the contact w/ basket, allowing fuel to flow
FAIL light in refueling system comes on when
1 of the 3 Inlet valves, or the vent/safety valve stay closed instead of opening
During air to air refuel operation, how do we understand that the selected qty has been reached?
ON light goes off (inlet valves and vent safety valve automatically close)
F.VENT comes on when
Fuel vent/safety valve fails to close when the operation is over
If after air refueling ON light stays on it means that
1 of the 3 inlet valves failed to close
What switch does activate Booster pump?
ENG/MSTR moved to ON
At what qty in the fuselage tank transfer valves open sending fuel to it from tips/pylons?
590kg
When tips are empty, how does the system maintain positive pressure in the fuselage tank?
W/ pressurized air flowing from empty tips to fuselage
Name the caution lights of the fuel system
F. UNBAL
F. LOW
F. VENT
F. PRSS
F. TRANS
When caution legend of fuel system comes on an audio “FUEL WARNING” is heard in the headset, except for what light?
F. VENT
Inverted Flight Sump capacity
14 l
Booster pump sends fuel to the engine feeding system at a pressure of
18psi
What is the pressure of the air used to cause fuel transfer?
4.5psi
In what case moving the FUEL TRANSFER SWITCH from pyl to tip does not produce any effect?
In case of batteries failure, or selecting BAT SWITCH to EMERG
Unusable fuel in fuselage tank
NIL
Once F. PRSS illuminates
It means that Booster pump is not working properly, therefore the engine driven pump ensures functionality of the engine for only 15’ at max power
Single point refueling pressure range
30-50psi
Fuselage tank qty
626kg
Wing tip tanks qty
803kg
Pylons qty
530kg
Max amount of fuel without pylons
1429kg
Max amount of fuel with pylons
1959kg
Fuel from the booster pump, before reaching the supply system flows into
Anular filter
When pylons are empty, what other light comes on warning us to move the transfer switch?
MASTER CAUTION
The fuel measuring system in the pylons
Doesn’t provide w/ qty but only if empty
When fuel is below bingo, fuel qty will appear
In amber background
Considerations when F. VENT comes on
Do not do aggressive maneuvers
Fuel transfer from the tips might not be working properly (considerations about a reduced range)
During refueling the fuel flows
From the fuselage tank to the tip tanks
For operating the refuel system on ground
Battery must be on
Green lights (2) in the Fuel Control Panel indicate that
The fuselage inlet valve and safety/ vent valve are open
and
Fuel Transfer valves are open
How can be understood from the Fuel Control Panel when we reached the desired qty of fuel in that tank?
Because the respective red light on the panel goes out
What does the Fuel Control Box do?
Used mainly for refueling ops.
Receives inputs from:
- A/R switch
- Refueling Control Panel
-AR/ON/FAIL push button
for opening and closing of 3 inlet valves and vent/safety valve
Communicates with EDAB
In the fuel system, pressure coming from air bled in the 8th stage of the compressor, is reduced to 4.5psi from
Pressure Reducing Valve
During A/A refueling, after how many kg above bingo the amber background caused by BINGO fuel will go out?
50kg
At what pressure F. PRSS comes on?
When fuel pressure produced by the booster pump is 3psi or less
What is the max fuel unbalance in the tips that produces 850kgm and 1100kgm reported in the ops limits?
850kgm -> 160kg unbalance tips
1100kgm -> 210kg unbalance tips
What is the normal fuel transfer rate?
41kg/min
